Structural design of automatic nozzle injection mo

Structural design of automatic nozzle injection mold for shower gel container

Abstract: through the structure and process analysis of a nozzle part of a shower gel container, the structural processes of rotating core pulling and spiral demoulding are introduced in detail

key words: nozzle injection mold rotating core pulling screw demoulding

1 process analysis of plastic parts

Figure 1 shows the automatic nozzle of a daily chemical container, the average wall thickness of the plastic part is 1.5mm, and the overall dimension is 23mm × 59mm × 30mm, the outer surface is smooth. However, the bottom contains external threads, and the threads have certain matching requirements, so it is necessary to set a thread removal mechanism; The nozzle part is in a curved shape. Generally, the core pulling mechanism can only complete straight-line core pulling, and cannot realize arc demoulding with a certain degree of curvature. The core pulling can only be carried out by rotating according to the center track line of the nozzle inner hole. Therefore, although the size of the product is small, the structure of the application is relatively complex

2 determination of mold structure

the material of this product is ABS, which has high strength, hardness, heat resistance and chemical resistance, good fluidity and small molding shrinkage; At the same time, considering the small size of the product, the latent gate with high automation can be used (see the enlarged figure at a in Figure 2). The line a in Figure 1 can be selected as the parting surface. In order to facilitate mold drawing, the parting surface is set at the maximum contour line of the round pipe at the nozzle of the nozzle. Due to the large batch of products and the high matching requirements of the thread part, the structure of the forced thread removal mold can not meet the requirements of the product use, and the productivity of manual screw demoulding is low, so it is appropriate to adopt mechanical automatic demoulding in the mold

according to the analysis and production requirements of plastic parts, the mold is designed as one mold and two cavities, as shown in Figure 2. The external power device is used to demould the thread by gear transmission, and the rotating core pulling part is realized by three times of mold parting

2.1 working process of gear core pulling part

Figure 2 shows that the right angle injection machine is used to open and close the mold, the transmission rod 24 is connected with the screw transmission device of the injection molding machine, and the screw core 13 is driven to rotate through the in mold transmission gears 19 and 25. In order to prevent relative sliding, the anti rotation pin is added to the rod 16 [1]. Through the rotation of the thread core 13, the thread part of the product can be made, which also makes the products of sell Royal gradually form three series: sports type, ordinary type and relaxed demoulding. In the mold opening process, only after the thread part is completely demoulded, the parting surface starts to open the mold at Figure 2

2.2 working process of rotating core pulling part

the first thing to consider in rotating core pulling is the power source. There are two kinds of methods most commonly used: first, the application of oil cylinder will make the mold structure slightly simpler, but the cost will increase. The second is to use the opening and closing mold of the mold to pull the core. This method can save the manufacturing cost and cooperate with the mechanical action of the mold, which has good flexibility. Since the arc angle of the core pulling of the product does not exceed 90 degrees, the latter method can be adopted for core pulling

in the mold opening process, after the thread part of the product completely separates from the thread core 13 for a certain distance, the parting surface will then open at (Figure 2) (see Figure 3 (a) for the partial Figure). At the moment of opening the mold, the locking block 1 moves relative to the baffle plate 27 with a straight groove and the fixed block 2 with an arc groove. First, the locking effect on the core pulling core 3 is cancelled, and the baffle plate 27 will always remain on the side of the rear mold until the mold is opened to the State B in Figure 3. Since the core pulling core 3 is installed in the sliding groove of the fixed block 2 on one side of the rear mold, when opening the mold, the core pulling core 3, in addition to being constrained by the straight groove of the baffle 27, also moves in the circular arc groove of the fixed block 2. After the parting surface reaches the opening limit, the core pulling core is in the position of figure C in Figure 3, which completes the whole circular arc core pulling process

2.3 points, otherwise it will enter the setting state) set the temperature mold surface opening and closing control device

in the whole mold action, there are many mold opening parts of the mold, with a total of three mold opening surfaces, as shown in Figure 2,,, from the mold opening process of Figure 3, we can see that in order to protect the core pulling core 3 from being stuck when the mold is opened, we must release the constraint of the locking block 1 at the first time of mold opening, and separate the mold at first; In order to ensure the smooth progress of the core pulling process, we must ensure that the parting surface does not move, and let the parting surface open the mold for core pulling action; After the core pulling action is completed, open the parting surface to help the product eject. Finally, take out the product and channel condensate with a manipulator

therefore, how to control the opening sequence of these three parting surfaces is the key to ensure the normal operation of the mold. Figure 4 shows the mold opening control device, and figure a shows the mold closing state. When the mold starts to act, because the pull plate 9 is stuck by the hook 5, all parts under the moving template 2 will be in a relatively static state, and the mold can only be opened on the surface between the top plate 1 and the moving template 2. When the limit plate 3 reaches the state shown in Figure B of Figure 4, the barb at the lower end of the limit plate 3 will push the hook 5 to make the pull plate 9 in a free PPS, peek, PI, PSF, high temperature PA LCP and other states; The mold continues to open, and the parting surface reaches the maximum opening state due to the action of limit screw 10. Due to the action of spring 12, the parting surface will then be opened on the surface to complete the arc core pulling process of the product. After the limiting screw 11 reaches the limit position (open 60mm), the parting surface will be opened on the surface to complete the ejection action of parts in the mold, as shown in Figure C (or figure 3, state d)

in this structure, in addition to the opening of the mold, it is also necessary to consider the closing of the mold. After the mold reaches the State C in Figure 4, the mold will close. Due to the addition of springs at the parting surface, the core pulling 3 in Figure 1 will be finally reset. If the priority resetting of the limit block 1 reaches the fully closed state, it will hinder the recovery of the core pulling 3, and even damage the corresponding parts. Therefore, A set of device must be added to make the core pulling core 3 reset preferentially. The device is shown in Figure 5. In order to make the parting surface reset finally, the interaction between hard block 2 and chuck 4 is applied to lock the parting surface, and the other two parting surfaces are closed first. Because the stroke of the clamping plate 4 is related to the inclination of the guide rod 7, it can be set that the clamping effect of the hard block 2 and the clamping plate 4 can be cancelled only when the parting surface is almost closed, and finally the parting surface is closed

in the mold structure, mechanical rotary core pulling and spiral demoulding are used to improve productivity, and additional devices are used to control the opening and closing of the mold, which greatly improves the automation of the mold. Its characteristic is that the mold is relatively complex, and it needs to be produced by the right angle injection molding machine with thread core pulling. The mold has no special ejection system, and the ejection is completely completed by the mold opening action. Moreover, the ejection is not complete, and the products need to be taken out by hand or manipulator. The latent gate can automatically remove the gate, and the ball disk friction pair can also improve the productivity to a certain extent